Fed-batch processes
describe a cultivation process in which the bioreactor is started with a smaller volume (20 % to 50 % of the maximum working volume). As soon as the key components are depleted or growth-limiting concentrations of metabolites are reached, fresh medium or a specially formulated solution (consisting of diverse components) is periodically or continuously added until the maximum working volume is reached. With a fed-batch strategy, the growth phase can be elongated and cell and product concentrations can be increased 28. See feeding, concentrated fed-batch processes and repeated fed-batch processes.